How do we decode a JSON object in Java?

#JSON is a lightweight, text-based and language-independent data exchange format. JSON can represent two structured types such as objects and arrays. We can decode JSON objects using JSONObject and JSONArray from json.simple API. JSONObject works as java.util.Map and JSONArray works as java.util.List.

In the example below, we can decode a JSON object.

Example

import org.json.simple.*;
import org.json.simple.parser.*;
public class JSONDecodingTest {
   public static void main(String[] args) {
      JSONParser parser = new JSONParser();
      String str = "[ 0 , {\"1\" : { \"2\" : {\"3\" : {\"4\" : [5, { \"6\" : { \"7\" : 8 } } ] } } }    } ]";
      try {
         Object obj = parser.parse(str);
         JSONArray array = (JSONArray)obj;
         System.out.println("2nd Array element: ");
         System.out.println(array.get(1));
         System.out.println();
         JSONObject object2 = (JSONObject) array.get(1);
         System.out.println("Field \"1\"");
         System.out.println(object2.get("1"));
         str = "{}";
         obj = parser.parse(str);
         System.out.println(obj);
         str = "[6,]";
         obj = parser.parse(str);
         System.out.println(obj);
         str = "[6,,3]";
         obj = parser.parse(str);
         System.out.println(obj);
      } catch(ParseException parseExp) {
           System.out.println("Exception position: " + parseExp.getPosition());
           System.out.println(parseExp);
      }
   }
}

Output

2nd Array element:
{"1":{"2":{"3":{"4":[5,{"6":{"7":8}}]}}}}

Field "1"
{"2":{"3":{"4":[5,{"6":{"7":8}}]}}}
{}
[6]
[6,3]

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